This invention relates to a battery comprising a casing provided with an electrolyte-accommodating chamber containing an electrolyte, at least two metal electrodes in contact with the electrolyte and having electrode terminals, and two metal-containing active materials which can each electrically conductively communicate with one electrode only, as well as a porous separator for separating the two metal-containing active materials.
Electric batteries are known per se.
The best-known electric battery is the lead battery consisting of a glass jar with an anode being provided with a lead layer and being dischared by means of a sulfuric acid electrolyte while emitting electrons, the cathode containing a layer of lead oxide which is converted into lead sulfate under the influence of the sulfuric acid electrolyte present by accepting electrons. Such a lead battery can be easily regenerated by reversing the aforesaid reactions.
Such lead batteries have now been improved to a maximum extent so that they deliver a power of 22 to 35 Whr/kg and a power per unit of time of 150 W/kg, their useful life span having been increased to 1500 complete charge and discharge cycles with a maximum degree of temperature and shock resistance. For traction purposes, however, the known lead battery has moderate qualities, while the corrosive sulfuric acid is not very attractive.
Furthermore, there is known a nickel-iron battery having a long useful life span but having relatively bad qualities.
Although the known nickel-zinc battery has very good qualities indeed, it has a relatively limited life span. It has been established that in these batteries the zinc electrode is the cause of the instability of the electric battery. For, in the discharged state, the zinc is present in the form of zinc oxide or zin hydroxide, whereas, when being charged, there occurs again metallic zinc which has, however, the tendency of forming dendrites, thus reducing the effective surface area and encouraging deformation of the electrode. Such deformation easily results in short circuiting. In addition, it seems that the nickel electrode is easily poisoned under the influence of zinc ions.
The EMF of a nickel-zinc battery is 1.7 V, whereas it is 1.3 V only in the case of a nickel-iron battery.
In its behavior, the known silver-zinc battery resembles the nickel-zinc battery, and produces higher energy densities and a higher discharge current, but it is less advisable for certain applications. In particular, the cost of silver renders this electric battery less attractive.
Finally, a nickel-cadmium battery can also be mentioned, which with respect to the discharging under short-circuit conditions, compares favorably with the others, but has only moderate qualities in other respects. Moreover, this battery has the drawback of the poisonous properties of cadmium.
A common drawback of all batteries known in the art is the fact that the velocity of their various reactions is determined by diffusion, i.e., the reaction velocity is limited.